Machinery used in the paper industry commonly employs large woven fabric belts which may be 150 feet long and 200 inches wide or more. A belt of this type is woven on large looms and then the opposite ends of the belt are woven together in a laborious process to form a seamless belt. It is critical to the paper making process that the woven seam be flawless. The process for forming the woven seam has, up to now, been done primarily by hand and by fraying the filaments at the opposite ends of the woven fabric belt and by then weaving the filaments together into the other end of the belt. Since these woven belts may comprise a densely woven fabric of very fine filaments or threads, the manual seam weaving process is exacting and time consuming. It is difficult for the seam weaver to grasp the individual filaments in the proper sequence, yet it is imperative that the seam weaver produce a perfect and continuous woven product. If the filaments are not woven together in the proper order, the fabric is worthless. The seam weaver must also take great care to be sure that the woven filaments are not twisted and such that each knuckle of the seam filaments is properly oriented with respect to the other threads of the fabric.
As a result of the extreme care which must be taken with the seam weaving process, manual seam weaving requires a considerable number of hours of work for wide belts. Due to the time required and the level of skill necessary, the seam weaving process is very expensive and forms a substantial portion of the cost of the finished product.
Due to the expense of this manual seam weaving process, efforts have been made to automate the method for forming a woven seam and endless woven fabric belts. Prior to the present invention, such efforts have been unsuccessful.
One prior art apparatus has been developed for use in combination with manual seaming and for forming the shed openings. This apparatus is intended to reduce some of the effort required by the seam weaver yet it still requires manual weaving operations. This apparatus employs Jacquard devices such as those produced by Samuel Dracup & Sons, Ltd., Lane Close Mills, Great Horton, Bradford West Yorkshire, England.
Another example of the prior art attempts at providing a mechanized means for forming a woven seam is illustrated in the German Koller et al. patent disclosure No. P 30 25 909.7-26, published Feb. 4, 1982. While this structure or apparatus purports to provide an automatic seam weaving machine, it includes a number of different deficiencies. For example, no functional method is provided by Koller for separating the warp threads one from another, nor does Koller provide a commercially suitable means for weaving the warp threads through the weft threads to thereby form the woven seam.